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SEED TESTING INTERNATIONAL APRIL 2026
• RULES DEVELOPMENT
The Fusarium species listed below were included 
in the validation study. The names are based 
on the taxonomy from the Species Fungorum 
database (indexfungorum.org). Note that the 
current name and taxonomy may change over 
time.
• Fusarium avenaceum (Fries) Saccardo
• Fusarium graminearum Schwabe
• Fusarium culmorum (W.G. Smith) Saccardo
• Fusarium crookwellense Burgess, Nelson & 
Toussoun
• Fusarium langsethiae Torp & Nirenberg
• Fusarium poae (Peck) Wollenweber
• Fusarium tricinctum (Corda) Saccardo
• Fusarium sporotrichioides Sherbakoff
• Fusarium pseudograminearum Aoki & 
O’Donnell
Method Execution
Seed samples with a recommended minimum 
sample size of 400 seeds are disinfected using 
a solution of sodium hypochlorite with 1% 
available chlorine. All seeds are transferred 
to potato dextrose agar (PDA) or malt agar 
(MA) plates and incubated for 7 d at 20 ±2 ˚C in 
Figure 2. a. Colony of Fusarium culmorum after 7 d incubation in darkness ©GEVES; b. Macroconidia 
of F. culmorum with methyl blue stain (×400) ©GEVES; c. Chlamydospores of F. sporotrichioides with 
methyl blue stain (×400) ©GEVES; d. F. sporotrichioides on spezieller nährstoffarmer agar (SNA) 
©GEVES; e. F. culmorum on carnation leaf-piece agar (CLA) with orange sporodochia ©SASA
darkness. After 7 d, each seed is examined by 
eye (Fig. 2a), looking for colonies arising from 
the seeds. Fusarium species are very diverse in 
colour (white, pink, yellow, orange), shape  
and size. The main species found on cereals  
are described at the end of the method, in a 
section called ‘Morphological criteria of main 
Fusarium on cereals’. Some isolates may be easily 
identified without further subculturing.  
Different criteria can be examined with 
a compound microscope (×100 – 1000 
magnification) (Figs 2b and 2c) to identify the 
Fusarium species by their morphology. When 
the identity of a colony remains uncertain, 
these colonies can be subcultured on spezieller 
nährstoffarmer agar (SNA) (Fig. 2d) or on 
carnation leaf-piece agar (CLA) (Fig. 2e) with 
incubation under near-ultraviolet (NUV) light 
to stimulate sporulation. This will help in 
facilitating identification on the level of conidia 
morphology.
Method Validation
The analytical specificity is the ability to detect 
target pests while not detecting closely related 
a
b
c
d
e

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